In silico screening of GMQ-like compounds reveals guanabenz and sephin1 as new allosteric modulators of acid-sensing ion channel 3
In silico screening of GMQ-like compounds reveals guanabenz and sephin1 as new allosteric modulators of acid-sensing ion channel 3
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DOI：
10.1101/704445
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发表时间：
2019-07
影响因子：
5.8
通讯作者：
Gerard Callejo;Luke A. Pattison;J. Greenhalgh;Sampurna Chakrabarti;Evangelia Andreopoulou;James R. F. Hockley;E. Smith;Taufiq Rahman
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文献类型：
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作者：
Gerard Callejo;Luke A. Pattison;J. Greenhalgh;Sampurna Chakrabarti;Evangelia Andreopoulou;James R. F. Hockley;E. Smith;Taufiq Rahman
酸感离子通道（asic）是电压无关的阳离子通道，可以检测细胞外ph值的降低。asic的失调是许多病理的基础。特别值得关注的是ASIC3，它被认为是酸致疼痛的关键传感器，并有助于建立由炎症引起的疼痛，如类风湿关节炎。因此，鉴定新的ASIC3调节剂以及了解这些化合物如何调节ASIC3的机制对于开发新的策略来抵消炎症中ASIC3活性失调的有害影响可能是重要的。在这里，我们报道了基于ASIC3特异性激动剂2-胍-4-甲基喹唑啉（GMQ）的新型ASIC3调节剂的鉴定。通过在gmq指导下对FDA批准的药物进行芯片筛选，选择5种化合物，并利用全细胞膜片钳电生理技术测试它们对大鼠ASIC3 （rASIC3）可能的调节作用。在所选择的药物中，胍那苯是一种α - 2肾上腺素能受体激动剂，对rASIC3产生与GMQ相似的作用，在中性pH下激活通道，增强其对轻度酸性刺激的反应。Sephin1是一种缺乏α2-肾上腺素能受体活性的胍那苯衍生物，已被认为是应激诱导蛋白磷酸酶1 （PPP1R15A）调节亚基的选择性抑制剂，在治疗多发性硬化症方面具有良好的治疗潜力。然而，我们发现，与胍苯基一样，sephin1在中性pH下激活rASIC3，并增强其对酸性刺激的反应，即sephin1是一种新的rASIC3调节剂。此外，对接实验表明，与GMQ一样，guanabenz和sephin1可能与rASIC3的非质子配体感应结构域相互作用。总的来说，这些数据证明了计算分析在识别新型ASIC3调节剂方面的实用性，这可以通过电生理分析进行验证，并可能导致开发出更好的靶向ASIC3的化合物来治疗炎症。
Acid-sensing ion channels (ASICs) are voltage-independent cation channels that detect decreases in extracellular pH. Dysregulation of ASICs underpins a number of pathologies. Of particular interest is ASIC3, which is recognised as the key sensor of acid-induced pain and is instrumental in the establishment of pain arising from inflammatory conditions, such as rheumatoid arthritis. Thus, the identification of new ASIC3 modulators and the mechanistic understanding of how these compounds modulate ASIC3 could be important for the development of new strategies to counteract the detrimental effects of dysregulated ASIC3 activity in inflammation. Here, we report the identification of novel ASIC3 modulators based on the ASIC3 specific agonist, 2-guanidine-4-methylquinazoline (GMQ). Through a GMQ-guided in silico screening of Food and Drug administration (FDA)-approved drugs, 5 compounds were selected and tested for their possible modulation of rat ASIC3 (rASIC3) using whole-cell patch-clamp electrophysiology. Of the chosen drugs, guanabenz, an α2-adrenoceptor agonist, produced similar effects to GMQ on rASIC3, activating the channel at neutral pH and potentiating its response to mild acidic stimuli. Sephin1, a guanabenz derivative that lacks α2-adrenoceptor activity, has been proposed to act as a selective inhibitor of a regulatory subunit of the stress-induced protein phosphatase 1 (PPP1R15A) with promising therapeutic potential for the treatment of multiple sclerosis. However, we found that like guanabenz, sephin1 activates rASIC3 at neutral pH and potentiates its response to acidic stimulation, i.e. sephin1 is a novel modulator of rASIC3. Furthermore, docking experiments showed that, like GMQ, guanabenz and sephin1 likely interact with the nonproton ligand-sensing domain of rASIC3. Overall, these data demonstrate the utility of computational analysis for identifying novel ASIC3 modulators, which can be validated with electrophysiological analysis and may lead to the development of better compounds for targeting ASIC3 in the treatment of inflammatory conditions.